From: Sven Eckelmann <sven@narfation.org>
To: b.a.t.m.a.n@lists.open-mesh.org
Cc: Sven Eckelmann <sven@narfation.org>
Subject: [RFC PATCH 1/4] batman-adv: Request iflink once in batadv-on-batadv check
Date: Mon, 28 Feb 2022 00:52:54 +0100 [thread overview]
Message-ID: <20220227235257.1324636-1-sven@narfation.org> (raw)
There is no need to call dev_get_iflink multiple times for the same
net_device in batadv_is_on_batman_iface. And since some of the
.ndo_get_iflink callbacks are dynamic (for example via RCUs like in
vxcan_get_iflink), it could easily happen that the returned values are not
stable. The pre-checks before __dev_get_by_index are then of course bogus.
Fixes: 3d48811b27f5 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
net/batman-adv/hard-interface.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/net/batman-adv/hard-interface.c b/net/batman-adv/hard-interface.c
index 59d19097..774a26c5 100644
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -149,22 +149,23 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev)
struct net *net = dev_net(net_dev);
struct net_device *parent_dev;
struct net *parent_net;
+ int iflink;
bool ret;
/* check if this is a batman-adv mesh interface */
if (batadv_softif_is_valid(net_dev))
return true;
+ iflink = dev_get_iflink(net_dev);
+
/* no more parents..stop recursion */
- if (dev_get_iflink(net_dev) == 0 ||
- dev_get_iflink(net_dev) == net_dev->ifindex)
+ if (iflink == 0 || iflink == net_dev->ifindex)
return false;
parent_net = batadv_getlink_net(net_dev, net);
/* recurse over the parent device */
- parent_dev = __dev_get_by_index((struct net *)parent_net,
- dev_get_iflink(net_dev));
+ parent_dev = __dev_get_by_index((struct net *)parent_net, iflink);
/* if we got a NULL parent_dev there is something broken.. */
if (!parent_dev) {
pr_err("Cannot find parent device\n");
--
2.30.2
next reply other threads:[~2022-02-27 23:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-27 23:52 Sven Eckelmann [this message]
2022-02-27 23:52 ` [RFC PATCH 2/4] batman-adv: Request iflink once in batadv_get_real_netdevice Sven Eckelmann
2022-02-27 23:52 ` [RFC PATCH 3/4] batman-adv: Don't expect inter-netns unique iflink indices Sven Eckelmann
2022-02-27 23:52 ` [RFC PATCH 4/4] batman-adv: Demote batadv-on-batadv skip error message Sven Eckelmann
[not found] ` <CAHhjh1P1WvsEP3zo7KGPmexiHCiZrOUrxA_7RR17_wZapUupqQ@mail.gmail.com>
2022-02-28 0:30 ` Sven Eckelmann
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